Antiviral therapy for chronic hepatitis B.

The infection rate of hepatitis B virus is approximately 1% in Japan, and about 1.5 million people are believed to be infected. After infection, some patients go into spontaneous remission and become asymptomatic carriers, while others develop cirrhosis or liver cancer due to repeated cycles of relapse and remission of hepatitis. For this reason, it is vital to determine the treatment needs based on the age, progress, and clinical status of each patient and to select the appropriate therapy method accordingly. Antiviral treatments for chronic hepatitis B include interferon (IFN) therapy and nucleoside analogues (lamivudine, adefovir, and entecavir (tenofovir is not approved for chronic hepatitis B in Japan at this point)) therapy. Treatment strategies are decided based on the patient age, viral load, presence/absence of HBeAg, and progression of fibrosis. This paper describes the IFN and nucleoside analogue therapies with regard to the therapeutic applicability and effectiveness of each method.